BONO (AP) — Two teenagers working as volunteers at a northeast Arkansas haunted house suffered severe burns when another worker poured paint thinner into a burning barrel, causing it to burst into flames, authorities said.

The fire broke out late Saturday at Nightmare Productions Haunted House on U.S. 63 between Jonesboro and Bono. The haunted house’s owner, Cody Russell, said they don’t yet know why the worker poured the chemical into the barrel but said he’s since been dismissed from the company.

“The only thing I could figure is they were trying to get a fire started because it was cold,” Russell said. “It was a bad judgment call.”

Craighead County sheriff’s deputy Dustin Norwood said the 13-year-old boy and 14-year-old boy both suffered second- and third-degree burns on their faces and necks, and the fire singed off most of their hair. The older teen also suffered burns on his arms and hands, authorities said.

The teens weren’t employees of the haunted house but were there as volunteers, Russell said.

“We were letting them have some fun scaring people,” he said.

Allen Jackson, father of the 13-year-old, told The Jonesboro Sun his son is still in pain but is trying to remain positive. He said his son suffered extensive burns from the incident.

“It was an accident, but it was a stupid accident that could have been avoided,” Jackson said.

Authorities are investigating whether to file criminal charges against the worker who poured the chemical into the barrel, police said. That worker, who hasn’t been identified, wasn’t injured in the fire.

Russell said none of the haunted house’s attractions used paint thinner, so it was unclear why the worker brought the chemical.

“We try to run a family-friendly environment without injuring anybody, and an adult was irresponsible,” Russell said. “We are incredibly sorry on top of everything.”